Structure for attachment of buttress material to anvils and cartridges of surgical stapler

ABSTRACT

A surgical stapler is provided having a pair of jaws including a staple cartridge and an anvil. Buttress material is releasably secured to at least one of the staple cartridge and the anvil. The buttress material includes a tab to releasably and frictionally engage the at least one of the staple cartridge and the anvil.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Continuation Application of U.S. patentapplication Ser. No. 12/418,763, filed on Apr. 6, 2009, now U.S. Pat.No. 7,950,561, which is a Continuation-in-Part Application of U.S.patent application Ser. No. 11/820,239, filed on Jun. 18, 2007, now U.S.Pat. No. 7,665,646, each of which is incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to attachment systems for staple linebuttress materials. More particularly, the present disclosure relates tosystems and methods of temporarily attaching staple line buttressmaterials to an anvil and staple containing cartridge of a surgicalstapling instrument.

2. Background of Related Art

Surgical stapling instruments, or “stapling devices”, are employed bysurgeons to sequentially or simultaneously apply one or more rows offasteners, e.g., staples or two-part fasteners, to body tissue for thepurpose of joining segments of body tissue together. Such devicesgenerally include of a pair of jaws or finger-like structures betweenwhich the body tissue to be joined is placed. When the stapling deviceis actuated, or “fired”, longitudinally moving firing bars contactstaple drive members in one of the jaws. The staple drive members pushthe surgical staples through the body tissue and into an anvil in theopposite jaw which crimps the staples closed. If tissue is to be removedor separated, a knife blade can be provided in the jaws of the device tocut the tissue between the lines of staples.

When stapling relatively thin or fragile tissues, it is important toeffectively seal the staple line against air or fluid leakage.Additionally, it is often necessary to reinforce the staple line againstthe tissue to prevent tears in the tissue or pulling of the staplesthrough the tissue. One method of preventing tears or pull throughinvolves the placement of a biocompatible fabric reinforcing material,or “buttress” material, between the staple and the underlying tissue. Inthis method, a layer of buttress material is placed against the tissueand the tissue is stapled in conventional manner. In more recentmethods, the buttress material is positioned on the stapling instrumentitself prior to stapling the tissue. An exemplary example of this isdisclosed in U.S. Pat. No. 5,542,594 to McKean et al. In McKean et al.,a tube of buttress material is slipped over the jaw of the stapler. Thestapler is then actuated to staple the subject tissue and secure thebuttress material between the tissue and staple line to reinforce thetissue and staple line.

Some novel surgical staplers utilize fasteners or clips to temporarilyconnect buttress material to the jaws of the staplers. However, in someinstances, it would be desirable to mold or machine structure into thejaws themselves to facilitate attachment of correspondingly structuredbuttress materials. It would be further desirable to provide suchstructure in a manner which does not interfere with the operation of aknife blade associated with the jaws.

SUMMARY

There is disclosed a surgical stapler having a pair of jaws including astaple cartridge and an anvil. At least one of the jaws includes atleast two longitudinally extending projections positioned at a first endof the first jaw. The surgical stapler also has a staple line buttressmaterial releasably affixed to the at least one jaw and includingrecesses for receipt of the at least two projections. In one embodimenteach of the at least two projections includes a neck portion and abulbous portion. In an alternative embodiment, each of the at least twoprojections is relatively straight. The at least one jaw includes alongitudinally extending knife slot, the at least two projections beingseparated by the knife slot.

In a further embodiment, the at least one jaw includes two sets of theat least two projections and the at least one jaw includes alongitudinally extending knife slot. The knife slot separates the twosets of the at least two projections.

In particular embodiments, the at least one jaw includes a post at asecond end and the buttress material includes a hole for receipt of thepost. In a first version, the post is split to allow passage of a knifetherebetween, whereas in a second version the post is solid.

In a specific embodiment, the post forms a mushroom shaped protrusionhaving a cap and the cap defines a flange for engagement with a portionof the buttress material.

In another embodiment the at least one jaw includes a pair of posts andthe buttress material includes a pair of holes for receipt of the pairof posts. Each post of the pair of posts is positioned adjacent anoutside edge of the buttress material. The at least one jaw alsoincludes a longitudinally extending slot such that the pair of posts areseparated by the slot.

In a particular embodiment, the at least one jaw includes alongitudinally extending slot and the post is positioned distally of adistal end of the slot and the buttress material has a hole for receiptof the post. The buttress material further includes a longitudinal slitextending through the area of the buttress material defining the hole.

There is disclosed an end effector of a surgical stapler includinghaving a pair of jaws including a staple cartridge and an anvil, atleast one of the jaws including at least one projection extendinglongitudinally at a first end of the at least one of the jaws and agroove positioned at a second end thereof, and a buttress materialreleasably affixed to the at least one jaw, the buttress materialincluding at least one aperture at a proximal end for receipt of the atleast one projection and a tab at a distal end configured to engage thegroove. The tab may be made from a material providing an internal biasor spring action. The at least one projection may be relatively straightwith respect to the at least one of the jaws. The at least oneprojection has a cross-section having a geometry that is suited tosecure the at least one projection to the at least one aperture, e.g., arectangular or a cross-shaped cross-section. Alternatively, the at leastone projection may be mushroom shaped. In an embodiment, the at leastone projection may include a neck portion and a bulbous head adjacent tothe neck portion, the at least one projection adapted to secure thebuttress material between the bulbous head and the at least one of thejaws. The at least one projection may be engaged with the least oneaperture in an interference fit. A longitudinal slit extending throughthe at least one of aperture may prevent tearing of the buttressmaterial during insertion of the at least one projection therein.Additionally, the at least one jaw may include a knife slot and theprojections and apertures may be positioned to allow passage of a knifetherein. The least one jaw may include a pair of the least oneprojection and the buttress material may include a pair of the least oneaperture for reception of the pair of the at least one projectiontherein. Audible confirmation of proper placement of the buttressretention material on the at least one jaw may be provided.

DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed interlocking buttressretention systems are disclosed herein with reference to the drawings,wherein:

FIG. 1 is a perspective view of a surgical stapling instrumentincorporating embodiments of retention systems for attachment of stapleline buttress materials to an anvil and staple containing cartridge ofthe surgical stapling instrument;

FIG. 2 is a enlarged perspective view of the distal end of the surgicalstapling instrument of FIG. 1;

FIG. 3 is a perspective view, with parts separated, of one embodiment ofan anvil and buttress material retention system;

FIG. 4 is a perspective view of the assembled anvil buttress materialretention system;

FIG. 5 is a top view of the distal end of the anvil buttress materialretention system of FIG. 4;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 4;

FIG. 7 is a perspective view, with parts separated, of the proximal endof the anvil buttress retention system of FIG. 4;

FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7;

FIG. 9 is a perspective view, with parts separated, of an alternativeembodiment of the proximal end of an anvil buttress retention system;

FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9;

FIG. 11 is a perspective view, with parts separated, of one embodimentof a staple containing cartridge and buttress material retention system;

FIG. 12 is a perspective view of the assembled cartridge buttressretention system of FIG. 11;

FIG. 13 is a top view of the proximal end of the cartridge buttressretention system of FIG. 12;

FIG. 14 is a top view of an alternative embodiment of a proximal end ofa cartridge buttress retention system;

FIG. 15 is a cross sectional view taken along line 15-15 of FIG. 12;

FIG. 16 is a perspective view, with parts separated, of the distal endof the cartridge buttress retentions system of FIG. 12;

FIG. 17 is a cross-sectional view taken along line 17-17 of FIG. 16;

FIG. 18 is a perspective view, with parts separated, of an alternativeembodiment of a distal end of cartridge buttress retention system;

FIG. 19 is a cross-sectional view taken along line 19-19 of FIG. 18;

FIG. 20 is a perspective view of, with parts separated, of a furtheralternative embodiment of a distal end of a cartridge buttress retentionsystem;

FIG. 21 is a cross-sectional view taken along line 21-21 of FIG. 20;

FIG. 22 is perspective view of the distal end of the surgical staplinginstrument of FIG. 1 positioned about a tissue section;

FIG. 23 is side view, partially shown in section, of the distal end ofthe surgical stapling instrument positioned about the tissue section;

FIG. 24 is a side view, partially shown in section, during initialactuation of the surgical stapling instrument of FIG. 1;

FIG. 25 is a perspective view of a stapled and divided tissue section;and

FIG. 26 is a cross-sectional view taken along line 26-26 of FIG. 25.

FIG. 27 is a perspective view, with parts separated, of an embodiment ofa staple containing cartridge and buttress material retention system;

FIG. 28 is a perspective view of the assembled cartridge buttressretention system of FIG. 27;

FIG. 29 is a bottom view of the proximal end of the cartridge buttressretention system of FIG. 28;

FIG. 30A is a perspective view of the distal end of the cartridgebuttress system, with parts separated, of an embodiment of a staplecontaining cartridge and buttress material retention system; and

FIG. 30B is a perspective view of the assembled cartridge buttressretention system of FIG. 30A.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed interlocking buttress materialretention systems for use with surgical stapling instruments will now bedescribed in detail with reference to the drawings wherein like numeralsdesignate identical or corresponding elements in each of the severalviews. As is common in the art, the term ‘proximal” refers to that partor component closer to the user or operator, i.e. surgeon or physician,while the term “distal” refers to that part or component further awayfrom the user.

Referring now to FIG. 1, there is disclosed a linear surgical staplinginstrument or surgical stapler 10 for use in stapling tissue andapplying layers of buttress material between the staples and underlyingtissue. An exemplary example of this type of surgical staplinginstrument is disclosed in U.S. Pat. No. 7,128,253, the entiredisclosure of which is incorporated by reference herein. Surgicalstapler 10 generally includes a handle 12 having an elongate tubularmember 14 extending distally from handle 12. A jaw assembly 16 ismounted on a distal end 18 of elongate tubular member 14. Jaw assembly16 includes a staple clinching anvil 20 and a staple containingcartridge or staple cartridge 22. Staple cartridge 22 may be permanentlyaffixed to elongate tubular member 14 or may be detachable and thusreplaceable with a new staple cartridge 22. Staple clinching anvil 20 ismovably mounted on distal end 18 of elongate tubular member 14 and ismovable between an open position spaced apart from staple cartridge 22to a closed position substantially adjacent staple cartridge 22.

Staple clinching anvil 20 is provided with a layer of anvil buttressmaterial 24 and staple cartridge 22 is provided with a layer ofcartridge buttress material 26 in the manners described in more detailhereinbelow. An anvil buttress retention system 28 is incorporated intoanvil 20 and anvil buttress material 24 and is provided to releasablysecure anvil buttress material 24 to staple clinching anvil 20.Likewise, a cartridge buttress retention system 30 incorporated intostaple cartridge 22 and cartridge buttress material 26 and is providedto releasably secure cartridge buttress material 26 to staple cartridge22. Anvil buttress material 24 and cartridge buttress material 26 areprovided to reinforce and seal staple lines applied to tissue bysurgical stapler 10.

Anvil buttress retention system 28 and cartridge buttress retentionsystem 30 are particularly configured to allow the respective buttressmaterials to be localized on inwardly facing surfaces of anvil 20 andstaple cartridge 22 in order to facilitate passage of surgical stapler10 into the body of a patient without risk of tearing or wrinkling ofthe respective buttress materials as surgical stapler 10 is insertedinto and manipulated within the body of a patient.

Surgical stapler 10 further includes a trigger 32 movably mounted onhandle 12. Actuation of trigger 32 initially operates to move anvil 20from the open to the closed position relative to staple cartridge 22 andsubsequently actuate surgical stapler 10 to apply lines of staples totissue. In order to properly orient jaw assembly 16 relative to thetissue to be stapled, surgical stapler 10 is additionally provided witha rotation knob 34 mounted on handle 12. Rotation of rotation knob 34relative to handle 12 rotates elongate tubular member 14 and jawassembly 16 relative to handle 12 so as to properly orient jaw assembly16 relative to the tissue to be stapled.

Referring to FIGS. 1 and 2, a driver 36 is provided to move anvil 20between the open and closed positions relative to staple cartridge 22.Driver 36 moves between a longitudinal slot 38 formed in anvil 20. Aknife blade (not shown) is associated with driver 32 to cut tissuecaptured between anvil 20 and staple cartridge 22 as driver 36 passesthrough slot 38.

Referring to FIG. 3, in order to move anvil 20 between the open andclosed positions, anvil 20 includes a proximal, angled or sloped edge 40configured to be engaged by driver 36 in order to cam anvil 20 to theclosed position. Slot 38 extends distally from sloped edge 40 andterminates in a transverse slot 42 which is configured to capture driver36 upon complete actuation of surgical stapler 10 to prevent any furtheractuation of surgical stapler 10. In order to secure staples provided bystaple cartridge 22 about the tissues and buttress materials, anvil 20is provided with longitudinally extending rows of staple clinchingpockets 44 located on either side of longitudinal slot 38.

Referring still to FIG. 3, anvil buttress retention system 28,incorporated into anvil 20 and anvil buttress material 24, will now bedescribed. Anvil buttress material 24, as well as cartridge buttressmaterial 26. The buttress material for the staple cartridge 22 and/oranvil 20 may be made from any biocompatible natural or syntheticmaterial. The material from which the buttress material is formed may bebioabsorbable or non-bioabsorbable. It should of course be understoodthat any combination of natural, synthetic, bioabsorbable andnon-bioabsorbable materials may be used to form the buttress material.

Some non-limiting examples of materials from which the buttress materialmay be made include but are not limited to poly(lactic acid), poly(glycolic acid), poly (hydroxybutyrate), poly (phosphazine), polyesters,polyethylene glycols, polyethylene oxides, polyacrylamides,polyhydroxyethylmethylacrylate, polyvinylpyrrolidone, polyvinylalcohols, polyacrylic acid, polyacetate, polycaprolactone,polypropylene, aliphatic polyesters, glycerols, poly(amino acids),copoly (ether-esters), polyalkylene oxalates, polyamides, poly(iminocarbonates), polyalkylene oxalates, polyoxaesters,polyorthoesters, polyphosphazenes and copolymers, block copolymers,homopolymers, blends and combinations thereof.

In embodiments, natural biological polymers are used in forming thebuttress material. Suitable natural biological polymers include, but arenot limited to, collagen, gelatin, fibrin, fibrinogen, elastin, keratin,albumin, hydroxyethyl cellulose, cellulose, hydroxypropyl cellulose,carboxyethyl cellulose, chitan, chitosan, and combinations thereof. Inaddition, the natural biological polymers may be combined with any ofthe other polymeric materials described herein to produce the buttressmaterial.

The buttress material may be porous or non-porous, or combinations ofporous and non-porous layers. Where the buttress material is non-porous,buttress material may retard or prevent tissue ingrowth from surroundingtissues thereby acting as an adhesion barrier and preventing theformation of unwanted scar tissue. Thus, in embodiments, the buttressmaterial possesses anti-adhesion properties. Techniques for formingnon-porous layers from such materials are within the purview of thoseskilled in the art and include, for example, casting, molding and thelike.

In embodiments, the buttress material is porous and possesses hemostaticproperties. Where the buttress material is porous, it has openings orpores over at least a portion of a surface thereof. Suitable materialsfor forming the porous layer include, but are not limited to foams(e.g., open or closed cell foams). In embodiments, the pores may be insufficient number and size so as to interconnect across the entirethickness of the porous layer. In other embodiments, the pores do notinterconnect across the entire thickness of the porous layer. In yetother embodiments, the pores do not extend across the entire thicknessof the porous layer, but rather are present at a portion of the surfacethereof. In embodiments, the openings or pores are located on a portionof the surface of the porous layer, with other portions of the porouslayer having a non-porous texture. Those skilled in the art reading thepresent disclosure will envision other pore distribution patterns andconfigurations for the porous layer.

Where the buttress material is porous, the pores may be formed using anymethod suitable to forming a foam or sponge including, but not limitedto the lyophilization or freeze-drying of a composition. Suitabletechniques for making foams are within the purview of those skilled inthe art. Porous buttress materials can be at least 0.2 cm thick, inembodiments from about 0.3 to about 1.5 cm thick. Porous buttressmaterials can have a density of not more than about 75 mg/cm² and, inembodiments below about 20 mg/cm². The size of the pores in the porousbuttress materials can be from about 20 μm to about 300 μm, inembodiments from about 100 μm to about 200 μm.

The buttress material may also include a reinforcement member. Thereinforcement member may be associated with a porous or non-porous layeror may be positioned between a non-porous layer and a porous layer ofthe buttress material. Alternatively, the reinforcement member may bepositioned entirely within one or more of the individual layers (i.e.,embedded within the porous layer, the non-porous layer, or both) of thebuttress material. It is also envisioned that the reinforcement membermay be positioned at the surface of one of the layers making up thebuttress material and, in embodiments, may be positioned at an exteriorsurface of the buttress material.

Some suitable non-limiting examples of reinforcement members includefabrics, meshes, monofilaments, multifilament braids, chopped fibers(sometimes referred to in the art as staple fibers) and combinationsthereof. Where the reinforcement member is a mesh, it may be preparedusing any technique known to those skilled in the art, such as knitting,weaving, tatting, knipling or the like. Where monofilaments ormultifilament braids are used as the reinforcement member, themonofilaments or multifilament braids may be oriented in any desiredmanner. For example, the monofilaments or multifilament braids may berandomly positioned with respect to each other within the buttressmaterial. As another example, the monofilaments or multifilament braidsmay be oriented in a common direction within the buttress material.Where chopped fibers are used as the reinforcement member, the choppedfibers may be oriented in any desired manner. For example, the choppedfibers may be randomly oriented or may be oriented in a commondirection. The chopped fibers can thus form a non-woven material, suchas a mat or a felt. The chopped fibers may be joined together (e.g., byheat fusing) or they may be unattached to each other. The chopped fibersmay be of any suitable length. For example, the chopped may be from 0.1mm to 100 mm in length, in embodiments, 0.4 mm to 50 mm in length. In anillustrative embodiment, the buttress material has randomly orientedchopped fibers that have not been previously fused together embeddedwithin in the buttress material.

It is envisioned that the reinforcement member may be formed from anybioabsorbable, non-bioabsorbable, natural, or synthetic materialpreviously described herein and combinations thereof. Wheremonofilaments or multifilament braids are used as the reinforcementmember, any commercially available suture material may advantageously beemployed as the reinforcement member.

In embodiments, at least one bioactive agent may be combined with thebuttress material and/or any of the individual components (the porouslayer, the non-porous layer and/or the reinforcement member) used toconstruct the buttress material. In these embodiments, the buttressmaterial can also serve as a vehicle for delivery of the bioactiveagent. The term “bioactive agent”, as used herein, is used in itsbroadest sense and includes any substance or mixture of substances thathave clinical use. Consequently, bioactive agents may or may not havepharmacological activity per se, e.g., a dye, or fragrance.Alternatively a bioactive agent could be any agent which provides atherapeutic or prophylactic effect, a compound that affects orparticipates in tissue growth, cell growth, cell differentiation, ananti-adhesive compound, a compound that may be able to invoke abiological action such as an immune response, or could play any otherrole in one or more biological processes.

Examples of classes of bioactive agents which may be utilized inaccordance with the present disclosure include anti-adhesives,antimicrobials, analgesics, antipyretics, anesthetics, antiepileptics,antihistamines, anti-inflammatories, cardiovascular drugs, diagnosticagents, sympathomimetics, cholinomimetics, antimuscarinics,antispasmodics, hormones, growth factors, muscle relaxants, adrenergicneuron blockers, antineoplastics, immunogenic agents,immunosuppressants, gastrointestinal drugs, diuretics, steroids, lipids,lipopolysaccharides, polysaccharides, and enzymes. It is also intendedthat combinations of bioactive agents may be used.

Anti-adhesive or anti-adhesion agents can be used to prevent adhesionsfrom forming between the buttress material and the surrounding tissuesopposite the target tissue. Some examples of these agents include, butare not limited to poly(vinyl pyrrolidone), carboxymethyl cellulose,hyaluronic acid, polyethylene oxide, poly vinyl alcohols andcombinations thereof.

Suitable antimicrobial agents which may be included as a bioactive agentin the buttress material of the present disclosure include triclosan,also known as 2,4,4′-trichloro-2′-hydroxydiphenyl ether, chlorhexidineand its salts, including chlorhexidine acetate, chlorhexidine gluconate,chlorhexidine hydrochloride, and chlorhexidine sulfate, silver and itssalts, including silver acetate, silver benzoate, silver carbonate,silver citrate, silver iodate, silver iodide, silver lactate, silverlaurate, silver nitrate, silver oxide, silver palmitate, silver protein,and silver sulfadiazine, polymyxin, tetracycline, aminoglycosides, suchas tobramycin and gentamicin, rifampicin, bacitracin, neomycin,chloramphenicol, miconazole, quinolones such as oxolinic acid,norfloxacin, nalidixic acid, pefloxacin, enoxacin and ciprofloxacin,penicillins such as oxacillin and pipracil, nonoxynol 9, fusidic acid,cephalosporins, and combinations thereof. In addition, antimicrobialproteins and peptides such as bovine lactoferrin and lactoferricin B maybe included as a bioactive agent in the bioactive coating of the presentdisclosure.

Other bioactive agents which may be included as a bioactive agent in thebuttress material in accordance with the present disclosure include:local anesthetics; non-steroidal antifertility agents;parasympathomimetic agents; psychotherapeutic agents; tranquilizers;decongestants; sedative hypnotics; steroids; sulfonamides;sympathomimetic agents; vaccines; vitamins; antimalarials; anti-migraineagents; anti-parkinson agents such as L-dopa; anti-spasmodics;anticholinergic agents (e.g. oxybutynin); antitussives; bronchodilators;cardiovascular agents such as coronary vasodilators and nitroglycerin;alkaloids; analgesics; narcotics such as codeine, dihydrocodeinone,meperidine, morphine and the like; non-narcotics such as salicylates,aspirin, acetaminophen, d-propoxyphene and the like; opioid receptorantagonists, such as naltrexone and naloxone; anti-cancer agents;anti-convulsants; anti-emetics; antihistamines; anti-inflammatory agentssuch as hormonal agents, hydrocortisone, prednisolone, prednisone,non-hormonal agents, allopurinol, indomethacin, phenylbutazone and thelike; prostaglandins and cytotoxic drugs; estrogens; antibacterials;antibiotics; anti-fungals; anti-virals; anticoagulants; anticonvulsants;antidepressants; antihistamines; and immunological agents.

Other examples of suitable bioactive agents which may be included in thecoating composition include viruses and cells, peptides, polypeptidesand proteins, analogs, muteins, and active fragments thereof, such asimmunoglobulins, antibodies, cytokines (e.g. lymphokines, monokines,chemokines), blood clotting factors, hemopoietic factors, interleukins(IL-2, IL-3, IL-4, IL-6), interferons (β-IFN, (α-IFN and γ-IFN),erythropoietin, nucleases, tumor necrosis factor, colony stimulatingfactors (e.g., GCSF, GM-CSF, MCSF), insulin, anti-tumor agents and tumorsuppressors, blood proteins, gonadotropins (e.g., FSH, LH, CG, etc.),hormones and hormone analogs (e.g., growth hormone), vaccines (e.g.,tumoral, bacterial and viral antigens); somatostatin; antigens; bloodcoagulation factors; growth factors (e.g., nerve growth factor,insulin-like growth factor); protein inhibitors, protein antagonists,and protein agonists; nucleic acids, such as antisense molecules, DNAand RNA; oligonucleotides; polynucleotides; and ribozymes.

Anvil buttress retention system 28 is provided to releasably secureanvil buttress material 24 to anvil 20 prior to stapling to tissue.Anvil buttress retention system 28 includes a distally raised region 46formed on an undersurface 48 of anvil 20. As best shown in FIGS. 3 and5, distally raised region 46 includes a pair of proximally extendingfingers or projections 50 and 52 configured to releasably secure adistal end of anvil buttress material 24 on anvil 20. As used herein,the term “projections” refer to those structures provided on the jaws ofthe instrument which resemble fingers and are configured to engagebuttress material positioned between the fingers in friction fitfashion. Projections 50 and 52 include respective necks 54, 56 andbulbous portions 58, 60 extending proximally from necks 54 and 56. Cutouts 62 and 64 are provided in a distal end 66 of anvil 20 forengagement with projections 50 and 52 of anvil 20. Cut outs 62 and 64are configured with respective necks 68, 70 and bulbous portions 72 and74 corresponding to necks 54, 56 and bulbous portions 58, 60 of anvil20. Projections 50 and 52 along with cutouts 62 and 64 form pairs ofinterlocking fingers to hold anvil buttress material 24 on anvil 20.

Anvil buttress system 28 further includes a post 76 formed at a proximalend 78 of anvil 20. Anvil buttress material 24 is provided with a hole80 at a proximal end 82 which is configured to engage post 76 andmaintain anvil buttress material 24 taut across undersurface 48 of anvil20.

As best shown in FIG. 3-6, post 76 is split into post halves 76 a and 76b defining a channel 84 therebetween. Channel 84 corresponds to slot 38in anvil 20 and allows for movement of driver 36, as well as the knifeassociated with driver 36, through slot 38 to close anvil 20 and cutanvil buttress material 24 in half after stapling.

Referring back for the moment to FIGS. 3 and 4, in order to assembleanvil buttress material 24 to anvil 20 using anvil buttress retentionsystem 28, cut outs 62 and 64 at distal end 66 of anvil buttressmaterial 24 are positioned over projections 50 and 52 on distally raisedregion 46 of anvil 20. Thereafter, anvil buttress material 24 is drawntaut proximally and hole 80 is positioned over post 76 at proximal end78 of anvil 20 to secure anvil buttress material 24 against undersurface48 of anvil 20.

Referring to FIGS. 7 and 8, there is disclosed an alternative embodimentof a retention system 86 for securing proximal end 82 of anvil buttressmaterial 24 to anvil 20 in a manner to allow passage of driver 36through slot 38 in anvil 20. Retention system 86 includes a mushroomshaped post or protrusion 88 having an enlarged cap 90 for placementthrough hole 80 in anvil buttress material 24. Cap 90 defines anunderside surface or flange 92 configured to engage anvil buttressmaterial 24. Similar to post 76 described hereinabove, protrusion 88 issplit into protrusion halves 88 a and 88 b defining a slot 94therebetween for passage of driver 36 and an associated knife blade. Cap90 assists in preventing premature release of proximal end 82 of anvilbuttress material 24. While not specifically shown, the area around hole80 may include a perforated area to facilitate separation of anvilbuttress material 24 from protrusion 88.

Referring to FIGS. 9 and 10, there is illustrated a further alternativeembodiment of a retention system 94 for retaining proximal end 82 ofanvil buttress material 24 on anvil 20. Anvil 20 is provided with a pairof horizontally spaced apart posts 96 and 98 positioned on either sideof slot 38. Proximal end 82 of anvil buttress material 24 is providedwith a pair of corresponding holes 100 and 102 configured to be engagedby posts 96 and 98, respectively. Posts 96 and 98 locate the areasecuring anvil buttress material 24 outwardly of slot 38 in anvil 20.This assists in maintaining outer edges 104 and 106 of anvil buttressmaterial 24 taut during use of surgical stapler 10.

Referring now to FIGS. 11 and 12, cartridge buttress retention system 30will now be described. As noted hereinabove, cartridge buttressretention system 30 is provided to retain cartridge buttress material 26on staple cartridge 22 prior to stapling of tissue. Staple cartridge 22generally includes a U-shaped outer channel 108 surrounding a staplecontaining insert 110. Staple containing insert 110 is provided withrows of staple pockets 112, the function of which is described in moredetail hereinbelow. A knife channel 114 passes longitudinally throughstaple containing insert 110 between rows of staple pockets 12.

Referring for the moment to FIGS. 11 and 15, cartridge buttressretention system 30 includes a post 116 formed at a distal end 118 ofstaple containing insert 110. Post 116 is similar to post 76 describedhereinabove and is split into halves 116 a and 116 b to accommodate thepassage of a knife blade to sever tissue and cartridge buttress material26. Cartridge buttress material 26 includes a corresponding hole 20formed in a distal end 122 of cartridge buttress material and configuredto fit over post 116 on staple containing insert 110.

Referring back to FIGS. 11 and 12, and with regard to FIG. 13, cartridgebuttress retention system 30 further includes a pair of distallyextending and relatively straight, spaced apart fingers or projections124 and 126 formed in a proximal end 128 of staple containing insert110. Projections 124 and 126 are positioned on either side of knifechannel 114 to secure cartridge buttress material 26 adjacent outeredges 130 and 132 of cartridge buttress material 26. Cartridge buttressmaterial 26 is provided with corresponding slots 134 and 136 formed in aproximal end 138 of cartridge buttress material 26. Slots 134 and 136are configured to engage projections 124 and 126 of staple containinginsert 110 in friction fit fashion to retain proximal end 138 ofcartridge buttress material 26 on proximal end 128 of staple containinginsert 110.

In order to assemble cartridge buttress retention system 30, hole 120 incartridge buttress material 26 is positioned over protrusion 116 ondistal end 118 of staple containing insert 110. Thereafter, proximal end138 of cartridge buttress material 26 is positioned over proximal end128 of staple containing insert 110. Slots 134 and 136 in anvil buttressmaterial 26 are forced over projections 124 and 126 on staple containinginsert 110 to engage anvil buttress material 26 with staple containinginset 110 in friction fit fashion.

Referring for the moment to FIG. 14, in an alternative embodiment,proximal end 128 of staple containing insert 110 is provided withmultiple sets of fingers or projections 140, 142 and 144, 146 positionedon either side of knife channel 114. Projections 140, 142 and 144, 146engage corresponding sets of slots 148, 150 and 152, 154, respectively,to secure proximal end 138 of cartridge buttress material 26 to proximalend 128 of staple containing insert 110. By providing multiple sets offingers on the jaw and corresponding slots in the buttress material, thesurface area available for frictional contact is increased providing amore secure connection. While not specifically shown, more than two setsof fingers and slots may be provided depending on the nature of thebuttress material and amount of frictional contact required.

Referring now to FIGS. 16-21, and initially with regard to FIGS. 16 and17, alternative methods of releasably securing buttress material to ajaw of a surgical instrument will now be described. A split protrusion156, similar to protrusion 88 described hereinabove, is formed on adistal end 118 of staple containing insert 110 and includes cap halves158 a and 158 b defining flanges 160 a and 160 b. Hole 120 in distal end122 of cartridge buttress material 26 fits over split protrusion 156 tosecure distal end 122 of cartridge buttress material 26 to distal end118 of staple containing insert 110.

Referring to FIGS. 18 and 19, distal ends 118 and 120 of staplecontaining insert 110 and cartridge buttress material 26 may be providedwith spaced apart posts 162,164 and spaced apart holes 166, 168,respectively. Posts 162, 164 and holes 166, 168 function substantiallyidentically to posts 96, 98 and holes 100, 102, described hereinabove,to secure distal end 122 of cartridge buttress material 26 to distal end118 of staple containing insert 110.

With respect to FIGS. 20 and 21, a solid, unsplit post 170 is providedon distal end 118 of staple containing insert 110. Post 170 is locateddistally of a distal end 172 of knife channel 114. A hole 174 isprovided in distal end 120 of cartridge buttress material 26 and alongitudinal slit 176 is formed through the area defining hole 174. Inuse, a knife associated with surgical stapler 10 cuts through cartridgebuttress material 26 through the length of knife channel 114. Aftercartridge buttress material 26 has been stapled to tissue and almostcompletely been cut in half, longitudinal slit 176 allows cartridgebuttress material 26 to separate in half without tearing or snagging.

Referring now to FIGS. 22 through 26, and initially with respect toFIGS. 22 and 23, the use of surgical stapler 10 to staple and divide atubular tissue section T will now be described. Initially, jaw assembly16, including anvil 20 and staple containing cartridge 22 are positionedaround the tissue T to be stapled. Driver 36 is in a proximal positionrelative to anvil slot 38. As best shown in FIG. 23, staple containinginsert 110 includes staples 178 positioned within individual staplepockets 180 of row of staple pockets 112. Staples 178 are of aconventional type and include a backspan 182 having a pair of legs 184and 186 extending from backspan 182. Legs 184 and 186 terminate intissue penetrating tips 188 and 190. Pushers 192 are located withinstaple pockets 180 and are positioned between staples 178 and the pathof a drive bar 194.

Referring now to FIG. 24, surgical stapler 10 is initially actuated bymovement of trigger 32 relative to handle 12 (FIG. 1) causing driver 36to move in the direction of arrow B and against sloped edge 40 of anvil20 thereby causing anvil 20 to be moved to the closed position relativeto staple cartridge 22. As drive bar 194 advances distally within staplecontaining insert 110, drive bar 194 urges pushers 192 upwardly againstbackspans 182 of staples 178 driving staples 178 through cartridgebuttress material 26, tissue T, anvil buttress material 24 and towardsstaple clinching pockets 44 in anvil 20. Tissue penetrating tips 188 and190 are bent within staple clinching pockets 44 in anvil 20 to therebysecure anvil buttress material 24 against tissue T while backspan 182secures cartridge buttress material 26 against tissue T.

While not specifically shown, upon full actuation of surgical stapler10, a knife blade associated with surgical stapler 10 and carried bydriver 36 cuts tissue T, as well as anvil buttress material 24 andcartridge buttress material 26 between the rows of now clinched staples102. Upon movement of anvil 20 to the open position spaced apart fromstaple cartridge 22, anvil buttress material 24 pulls away from anvil 20and cartridge buttress material 26 pulls away from staple cartridge 22.Specifically, distal end 122 of cartridge buttress material 26 is cutthrough by the knife and is released from post 116. Proximal end 138 ofcartridge buttress material 26 pulls free from longitudinal projections124, 126 at proximal end 128 of staple containing insert 110. Likewise,distal end 66 of anvil buttress material 24 pulls free from proximallyextending projections 50, 52 and proximal end 82 of anvil buttressmaterial 24 pulls free from post 78.

The resulting tissue T, divided and stapled closed with staples 178, isbest illustrated in FIGS. 25 and 26. Specifically, cartridge buttressmaterial 26 is secured against tissue T by backspans 182 of staples 178and anvil buttress material 24 is secured against tissue T by the nowclinched tissue penetrating tips 188 and 190 of staples 178. In thismanner, anvil buttress material 24 and cartridge buttress material 26are stapled to tissue T thereby sealing and reinforcing these staplelines created by staples 178.

Referring now to FIGS. 27-29, cartridge retention system 500 will now bedescribed to retain cartridge buttress retention material 526 on astaple cartridge 522 prior to the stapling of tissue. As shown in FIGS.27 and 28, at least one longitudinally extending projection 532 ispositioned at a first end of the staple cartridge 522 and a groove 530is positioned at a first end thereof. The staple cartridge 522 mayinclude at least two longitudinally extending projections 532, the atleast two projections 532 being separated by a knife slot 540. Thebuttress retention material 526 includes at least one aperture 531 forthe receipt of the projections 532 and a tab 535 at a distal end of thebuttress retention material 526 configured to engage the groove 530. Tab535 extends horizontally and distally from the distal end of thebuttress retention material 526. Preferably, the tab 535 extends along acentral axis of the buttress retention material 526 and has a narrowerwidth relative to a width of the buttress retention material 526. Thedistal end of the tab 535 curves downwardly to couple with the groove530 of the staple cartridge. The tab 535 may provide an internal bias orspring action due to the resiliency of the material from which the tab535 is made. Consequently, when the tab 535 is positioned to engage thegroove 530, the tab 535 snaps into a locked position with the groove530.

FIG. 28 shows the buttress material 528 releasably affixed to the staplecartridge 522. In order to assemble the cartridge buttress retentionsystem 500, apertures 531 are positioned over projections 532 on thefirst end of the staple cartridge 522. The projections 532 may beslightly larger in size than the apertures 531, thereby providing aninterference fit upon insertion of the projections 532 into theapertures 531. The projections 532 and the corresponding apertures 531may have any geometry best suited for retaining the projections 532within the apertures 531. The projections 532 may be relatively straightor may have a shape including but not limited to rectangular andcross-shaped geometries. Upon positioning the apertures 531 over theprojections 532, the tab 535 of the buttress retention material 526 ispositioned over the groove 530. Once so positioned, the tab 535 isforced over the groove 530, as shown best in FIG. 29, thereby securingthe buttress retention material 526 to the staple cartridge 522. Anaudible indicator, e.g., a clicking sound, may confirm placement of thebuttress retention material 526 on the staple cartridge 522.

In a further embodiment, shown in FIGS. 30A and 30B, a buttressretention system 600 is provided including a buttress retention material626 and a staple cartridge 622. The buttress retention material 626includes apertures 631 adapted to receive one or more projections 635,the projection 635 including a bulbous head 632 and a neck portion 633.The staple cartridge 622 may include at least two projections 635, theat least two projections 635 being separated by a knife slot 640. A slit634 may extend longitudinally from the aperture 633 to prevent tearingor snagging upon insertion of the projection 635 into aperture 633. Atab 637 at an end of the buttress retention material 626 is engagablewith a groove 630 at an end of the staple cartridge 622.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example, various numbers ofinterlocking fingers or projections may be provided to increase thefrictional contact between a jaw and an associated buttress material.Further, the disclosed buttress materials may be provided with variousperforated regions to facilitate release from the disclosed fingers orprojections and posts. Therefore, the above description should not beconstrued as limiting, but merely as exemplifications of particularembodiments. Those skilled in the art will envision other modificationswithin the scope and spirit of the claims appended hereto.

1. A staple cartridge, comprising: a housing including a proximalportion and a distal portion, the housing defining a surface including aplurality of staple pockets formed in a tissue contacting surfacethereof for the reception of staples therein; and a buttress materialincluding a proximal and a distal portion, the buttress materialreleasably securable to the surface of the housing atop of the staplepockets, the distal portion of the buttress material defining a distalend having a tab extending distally therefrom, the tab having a narrowerwidth relative to the buttress material and the distal portion of thehousing defining a groove, the tab configured to be releasably securedto the groove.
 2. The staple cartridge of claim 1, wherein the tab isfriction fit into the groove.
 3. The staple cartridge of claim 1,further comprising a knife blade and a knife channel, the knife bladereceivable through the knife channel.
 4. The staple cartridge of claim3, wherein the buttress material overlies the knife channel.
 5. Thestaple cartridge of claim 4, wherein the knife blade severs the buttressmaterial as the knife blade travels through the knife channel.
 6. Thestaple cartridge of claim 3, wherein the groove is disposed distal ofthe knife channel and wherein the tab is friction fit within the groove.7. The staple cartridge of claim 1, wherein the staple cartridgeincludes at least one projection extending from the tissue contactingsurface, and wherein the buttress material includes at least oneaperture for receiving a respective one of the at least one projection.8. A staple cartridge, comprising: a housing including a proximalportion and a distal portion, the housing defining a surface including aplurality of staple pockets formed in a tissue contacting surfacethereof for the reception of staples therein, wherein the distal portionof the housing defines a groove and wherein the housing includes atleast one projection extending from the tissue contacting surface; and abuttress material including a proximal and a distal portion, thebuttress material releasably securable to the surface of the housingatop of the staple pockets, the distal portion of the buttress materialdefining a distal end having a tab extending distally therefrom, the tabhaving a narrower width relative to the buttress material, the tabconfigured to be releasably secured in the groove, and wherein thebuttress material includes at least one aperture for receiving arespective one of the at least one projection.
 9. The staple cartridgeof claim 8, wherein the tab is friction fit into the groove formed inthe housing of the staple cartridge.
 10. The staple cartridge of claim9, wherein the groove is disposed distal of the knife channel andwherein the tab is friction fit within the groove.
 11. The staplecartridge of claim 8, further comprising a knife blade and a knifechannel, the knife blade receivable through the knife channel.
 12. Thestaple cartridge of claim 11, wherein the buttress material overlies theknife channel.
 13. The staple cartridge of claim 12, wherein the knifeblade severs the buttress material as the knife blade travels throughthe knife channel.
 14. A surgical stapler, comprising: a handle; and anend effector connected to the handle assembly and operable by thehandle, the end effector supporting a replaceable staple cartridge, thestaple cartridge including: a housing including a proximal portion and adistal portion, the housing defining a surface including a plurality ofstaple pockets formed in a tissue contacting surface thereof for thereception of staples therein; and a buttress material including aproximal and a distal portion, the buttress material releasablysecurable to the surface of the housing atop of the staple pockets, thedistal portion of the buttress material defining a distal end having atab extending distally therefrom, the tab having a narrower widthrelative to the buttress material and the distal portion of the housingdefining a groove, the tab configured to be releasably secured to thegroove.
 15. The surgical stapler of claim 14, wherein the staplecartridge includes a first end and a second end, at least one projectionextends from the first end of the staple cartridge, the groove ispositioned at the second end of the staple cartridge, the buttressmaterial includes at least one aperture at a proximal end for thereception of the at least one projection therein, the buttress materialincludes at least one tab at a distal end of the buttress material, theat least one tab is friction fit into the groove of the staplecartridge.
 16. The surgical stapler of claim 14, wherein the buttressmaterial defines a tab that is friction fit into the groove formed inthe housing of the staple cartridge.
 17. The surgical stapler of claim14, wherein the surgical stapler includes a knife blade and the staplercartridge defines a knife channel, the knife blade receivable throughthe knife channel.
 18. The surgical stapler of claim 17, wherein thebuttress material overlies the knife channel.
 19. The surgical staplerof claim 17, wherein the knife blade is actuatable by the handle andsevers the buttress material as the knife blade travels through theknife channel.